Summary: To investigate the expression and clinical significance of p27kip1 protein in primary liver cancer, the expression of p27kip1 protein and the relationship with clinicopathological factors were studied in primary liver cancer by using SABC immunohistochemical staining in specimens of 40 cases of primary liver cancer and 20 cases of liver cirrihosis. Our results showed that positive expression rate of p27kip1 protein in primary liver cancer was 37.5 % (15/40), which was lower than that in benign lesion of liver 80.0 % (16/20, P<0.01). The expression level of p27kip1 protein in primary liver cancer showed significant differences in tumor size, Edmonson histological grade, portal invasion, lymph node metastasis, TNM stage (P<0.05, for all), but not significantly correlated with patient’s age and histological types. Log rank test showed that the p27kip1 expression was significantly related with prognosis of the patients (P<0.05), and the prognosis of the patients with p27kip1 positive expression was markedly better than that of those with p27kip1 negative expression. It is concluded that the expression of p27kip1 was significantly related clinicopathological factors of primary liver cancer. p27kip1 protein may be used as a novel tumor marker for primary liver cancer. Summary: To investigate the expression and clinical significance of p27kip1 protein in primary liver cancer, the expression of p27kip1 protein and the relationship with clinicopathological factors were studied in primary liver cancer by using SABC immunohistochemical staining in specimens of 40 cases of primary liver cancer and 20 cases of liver cirrihosis. Our results showed that positive expression rate of p27kip1 protein in primary liver cancer was 37.5% (15/40), which was lower than that in benign lesion of liver 80.0% (16/20, P <0.01). The expression level of p27kip1 protein in primary liver cancer showed significant differences in tumor size, Edmonson histological grade, portal invasion, lymph node metastasis, TNM stage (P <0.05, for all), but not significantly correlated with patient’s age and histological types. Log rank test showed that the p27kip1 expression was significantly related with prognosis of the patients (P <0.05), and the prognosis of the patients with p27kip1 posit ive expression was markedly better than that of those with p27kip1 negative expression. It is that that expression of p27kip1 was significantly related to clinicopathological factors of primary liver cancer. p27kip1 protein may be used as a novel tumor marker for primary liver cancer.